DID YOU HEAR THAT What did the hammer

DID YOU HEAR THAT?

What did the hammer say to the anvil?

Let’s go stirrup some trouble

Auditory Localization- vid clip ■ The brain calculates a sound’s location by using these differences. ■ Timing (. 000027 sec. Diff) ■ Sound travels @ 750 mph ■ Sound Waves Loudness (amplitude) Pitch (frequency) ■ ■ Long waves; low frequency/low pitch Short waves; high frequency/high pitch

Auditory Process: Perceiving Pitch Frequency Theory: Measures neural impulses travelling the auditory nerve. (lower pitch sounds travel at lesser speed) Place Theory: Links the pitch we hear with the place that is stimulated in the cochlea (different pitches of sound affect different places within cochlea)

Theories of Hearing ■ Place theory ■ Pitch (how high or low something is) is determined by location of vibration along the basilar membrane ■ But this doesn’t explain low-pitch since we haven’t found specific positions for those on the bm ■ Frequency theory ■ If the frequency of the sound is 100 waves per second then the neuron fires at 100 pulses per second. ■ Yet, we can hear frequencies above 1000 waves per second but can’t fire neurons faster than 1000 pulses per second. ■ Volley Principle ■ Pattern of sequential firing creates a combined high frequency signal

Mc. Gurk Effect ■ When visual cues and sounds conflict!

Sensory Interaction ■ ■ Different sensory modules exist because signals received by the sense organs stimulate different nerve pathways leading to different areas of the brain. Synesthesia ■ A condition in which stimulation of one sense also evokes another.

Hearing Loss §Conduction Hearing Loss: Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea. § Surgery §Sensorineural Hearing Loss: Hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerve, also called nerve deafness. § § Hearing aid to amplify sound Cochlear Implant

Cochlear Implants Cochlear implants are electronic devices that enable the brain to hear sounds. Wolfgang Gstottner. (2004) American Scientist, Vol. 92, Number 5. (p. 437) Cochlear Implant

Starburst time!! (146 -150) ■ Conduct the experiment and answer the following questions with your partner. 1. What factors influence taste? 2. What are the 5 basic tastes? 3. Explain sensory interaction & provide an example. 4. Describe the process of smell?

Olfactory Nerve: (Smell) ■ Receptors that send information about odors Did you hear about they guy down the road that went to work and smelled?

He worked at the ol’ factory.

Smell Like taste, smell is a chemical sense. Odorants enter the nasal cavity to stimulate 5 million receptors to sense smell. Unlike taste, there are many different forms of smell.

Olfactory System The brain’s circuitry for smell also connect with areas involved in memory storage.

■ The neurons of the nose wanted to date the neurons of the mouth. They had good taste.

Taste is a chemical sense ■ ■ Photograph of tongue surface (top), magnified 75 times. 10, 000 taste buds line the tongue and mouth. ■ ■ Taste receptors are down inside the “bud” Children have more taste buds than adults.

Different Tastes ■ Different people have different tastes based on: ■ ■ Survival Culture Learning Food attractiveness

Taste ■ Four basic tastes ■ ■ ■ Sweet Salty Sour Bitter Recent discovery of fifth taste ■ Umami – Japanese word meaning savory taste. People taste umami through receptors for glutamate, commonly found in its salt form as the food additive monosodium glutamate (MSG)

Umami

Age, Gender, and Smell Ability to identify smell peaks during early adulthood, but steadily declines after that. Women are better at detecting odors than men.

Smell and Memories The brain region for smell (in red) is hard wired into brain regions involved with memory (limbic system – amygdala and the hippocampus). That is why strong memories are made through the sense of smell.

Which of our senses do you believe is most AND least vital to our existence? Explain.

Touch ■ ■ Skin is the largest sense organ There are receptors for pressure, temperature, and pain Touch appears to be important not just as a source of information, but as a way to bond with others Touch Localization ■ Touch localization depends on the relative lengths of the pathways from the stimulated parts to the brain.

Pain tells the body that something has gone wrong. Usually pain results from damage to the skin and other tissues. A rare disease exists in which the afflicted person feels no pain. AP Photo/ Stephen Morton Ashley Blocker (right) feels neither pain nor extreme hot or cold.

Born with no Pain- Gabby ■ How would being born without the ability to perceive pain influence you?

Revised Reducer-Augmenter Scale ■ Total scores can range from 21 to 126, with lower scores reflecting a tendency toward “reducing” and higher scores reflecting a tendency toward “augmenting. ” ■ People with low pain tolerance have a nervous system that amplifies, or augments, sensory stimulation. People with high pain tolerance have a nervous system that dampens, or reduces, the effects of sensory stimulation.

Gate-Control Theory Melzak and Wall (1965, 1983) proposed that our spinal cord contains neurological “gates” that either block pain or allow it to be sensed.

Gate Control Theory ■ ■ ■ Spinal cord contains small nerve fibers that conduct most pain signals It also contains larger fibers that conduct most other sensory signals When tissue is injured small nerve fibers activate and open the neural gate Large fiber activity shuts that gate Thus if you stimulate gate closing activity by massage electrical signal or acupuncture you can disrupt the pain message. The brain can close this gate too!

Phantom Limb - shorter ■ ■ Why do some people feel pain in limbs that have been amputated? How do you treat pain in absent limbs?

The Environment Within ■ Kinesthesis (Kinesthetic sense, kinesthesia) ■ ■ ■ The sense of body position and movement of body parts; also called proprioception. Ian Waterman vid. clip Equilibrium (vestibular sense) ■ The sense of balance. Vision interacts with motion/balance ■ Optic flow- vid. Clip ■ Semicircular Canals (fluid filled) ■ Sense organs in the inner ear, which contribute to equilibrium by responding to rotation of the head.

Vestibular Sacs

Vestibular Senses ■ ■ Vestibular senses provide information about equilibrium and body position Fluid moves in two vestibular sacs Vestibular organs are also responsible for motion sickness Motion sickness may be caused by discrepancies between visual information and vestibular sensation

Why do we feel dizzy? ■ The inner parts are open spaces filled with fluid. The inside walls of the spaces are covered with tiny hairs. Each hair is connected to a nerve cell that carries signals to the brain. When the head moves, the fluid sloshes around and bends the hairs. As each hair bends, it makes its nerve cell send a signal, telling the brain about that movement. ■ When we spin around, the fluid starts spinning, too. That gives us the sensation of spinning. When we stop, the fluid keeps moving (and bending tiny hairs and signaling the brain). That may make us feel that we are spinning backward. We call that "feeling dizzy. "